Research will continue in five major areas: Project 1 - A. Factors influencing the enhancement or the inhibition of bone resorption and formation. B. Mechanism of action of various bone remodelinn factors. Project II - A. The role of collagenase and other factors influencing degradation of bone collagen. B. The effect of parathyroid extract and other bone resorption-stimulating factors on the nature of the new bone collagen formed in a bone remodeling system. Projeect III - A Pharmacological Approach to the Treatment of Periodontal Syndrome in Beagle Hounds.